Cue ball angle computer including a curved mirror for indicating an impact point



Aug. 26, 1969 M. H. HORAN 3,463,593

CUE BALL ANGLE COMPUTER INCLUDING A CURVE!) MIRROR FOR INDICATING ANIMPACT POTN'I Filed April 6, 1966 2 Sheets-Sheet I! ,drrakmsys Aug. 26,1969 M. H. HORAN 3,463,593

curs mu, ANGLE uomuwa INCLUDING A ounvmu MIRROR FOR INDICAT'INC ANIMPACT POINT v Filed April L5, 1966 2 Sheets-Sheet 2 M a zmz UnitedStates Patent Olfice 3,463,593 Patented Aug. 26, 1969 CUE BALL ANGLECOMPUTER INCLUDING A CURVED MIRROR FOR INDICATING AN IM- PACT POINTMichael H. Horan, 2155 Bayard Ave., St. Paul, Minn. 55116 Filed Apr. 6,1966, Ser. No. 540,734 Int. Cl. G01c 1/06; G02b 27/32; G01b 11/26 US.Cl. 356-142 7 Claims ABSTRACT OF THE DISCLOSURE A cue ball anglecomputer for locating an impact point on a pool table cushion rail for acue ball. The computer has a one-half hemispherical shaped mirror whichreflects a diverging image of the entire top of a pool table. Indicialines divide the reflecting surface of the mirror on opposite sides of avertical plane bisecting the mirror. When the cue ball and selected ballangle of incidence and the angle of reflection are equal, a pointer onthe computer will indicate a point on the cushion rail which the cueball must hit in order to hit the selected ball.

This invention relates to a device for indicating the point of impact ofa cue ball on a cushion rail which the cue ball must strike to hit aselected ball. More particularly the invention is a cue ball anglecomputer used to accurately locate a point on a pool table cushion railwhich the cue ball must hit to complete a successful bank shot ordetermine if it is impossible to perform a bank shot from a cushionrail.

It is known that a cue ball, when hit dead center with a cue, willalways rebound from a cushion rail at precisely the same angle to therail as the cue ball entered the cushion rail. This physical phenomenonis identical to the light reflection law wherein the angle of incidenceis equal to the angle of reflection. The angle computer of thisinvention utilizes the light reflection law to accurately locate thepoint on the pool table cushion rail which must be hit by a cue ball inorder to complete a successful bank shot.

Briefly described, the cue ball angle computer comprises a base having asubstantially flat surface used t horizontally position the computer onthe horizontal playing surface of a billiard table. Projected upwardlyfrom one side of the base is an upright flat surface adapted to engagethe horizontal edge of a cushion rail longitudinally locating thecomputer along the rail. A convex light reflecting means mounted on thebase projects forwardly from the upright surface to produce a divergingimage of the entire pool table surface. The light reflecting means isone-half of a hemispherical shape mirror having a convex curved shape invertical cross section which refleets a diverging image of the entirepool table surface from any location on the cushion rail. Location linesare used in conjunction with light reflecting means to provide a visualindex indication of the cue ball relative to the other balls on thetable. The location lines are appropriately identified to accuratelyequate the angles between cushion rail and one ball image and thecushion rail and the selected ball image. When these angles are equal apointer on the computer will indicate the point on the cushion railwhich the cue ball must hit in order to hit the selected ball. Ifanother ball is viewed in the light reflecting means between the cueball and the ball desired to be hit, it is impossible to hit the firstball with a bank shot from the particular cushion rail. The computer canbe used to determine if additional bank shots are available from any ofthe other three cushion rails.

In the drawings:

FIGURE 1 is a plan view of a billiard table showing the cue ball anglecomputer of this invention used to determine the point of impact of acue ball on the cushion rail which the cue ball must strike to hit aselected ball;

FIGURE 2 is an enlarged plan view of the cue ball angle computer ofFIGURE 1 showing the images of the cue ball and the ball selected to behit by the cue ball;

FIGURE 3 is a front elevational view of the angle computer of FIGURE 2;

FIGURE 4 is an enlarged sectional view taken along the line 44 of FIGURE1, looking in the direction of the arrows;

FIGURE 5 is a top plan view of a modification of the cue ball anglecomputer of this invention;

FIGURE 6 is a sectional view taken along the line 66 of FIGURE 5;

FIGURE 7 is a top plan view of a further modification of the cue ballangle computer of this invention;

FIGURE 8 is a front elevational view of the angle computer of FIGURE 7;and

FIGURE 9 is a side elevational view of the angle computer of FIGURE 7.

Referring to FIGURE 1 of the drawing, there is a table indicatedgenerally at 10 shown as a conventional billiard table having arectangular, flat and horizontal top surface 11 and upright cushionrails 12 located around the periphery of top surface 11. Side pockets 13equally separate each of the side cushion rails. Corner pockets 14 arelocated in each corner of the table. Table 10 may be a billiard table,pool table, bumper pool table or like tables used in playing the gamesof billiards, pool and the like.

Positioned on playing surface 11 is a cue ball 16 separated from a firstball 17, a second ball 18, and a third ball 19. Cue 21 is in position tostrike cue ball 16 impelling it toward side cushion rail 12 at an impactpoint 22 to complete a bank shot to strike first ball 17 as indicated bythe broken line paths of movement of one ball 16. To accomplish thisshot cue ball 16 must strike cushion rail 12 at point 22. This point isusually determined by a sight calculation with reference to whitediamond markings on the top of the cushion rail of the angle of movementof the cue ball toward side rail 12 and equal angle of movement of thecue ball away from side rail 12.

The angle computer of this invention, indicated generally at 23, is usedto accurately determine point 22 so that the cue ball 16 will reboundfrom cushion rail 12 and hit first ball 17 thereby completing asuccessful bank shot. Under these circumstances the angle of incidence24 is equal to the angle of reflection 26.

To determine the impact point 27 on cushion rail 12 which cue ball 16must strike in order to hit third ball 19, computer 23 is moved alongcushion rail 12 to a new position as shown in broken lines until the cueball 16 is angularly aligned with third ball 19. At this position balls16 and 19 are visible at complementary locations on the computer. Whenone ball 16 is hit dead center with the cue, as indicated by arrow 28,cue ball 16 will strike point of impact 27, rebound from cushion rail 12and strike third ball 19 as shown in broken lines.

Referring to FIGURES 2, 3 and 4, angle computer 23 is located on topsurface 11 adjacent cushion rail 12 with the image 16A of cue ball 16and the corresponding image 17A of first ball 17 shown in broken linesat complementary portions of the computer. At this location the computerindicates impact point 22 which cue ball 16 must strike in order torebound oif cushion rail 12 and strike first ball 17. The computer 23comprises a semicircular flat base 29 having a fiat bottom 30 positionedon the horizontal top surface 11 of table 10. Secured to the top of base29 is a segment of a sphere indicated generally at 31 having a lightreflecting mirror surface 32 of a general convex shape. Surface 32 inplane (FIGURE 2) has a semicircular or one-half hemispherical outlineand in transverse section (FIGURE 4) a convex curvature. Anon-reflecting horizontal band 33fis located below the light reflectingsurface. A similar semi-circular non-reflecting top band 34 locatedabove surface 32 separates surface 32 from a top light reflectingsurface 35. The non-reflective surfaces may be black to provide maximumcontrast with light reflecting surface 32. Surface 32 may be a polishedmetal, plated metal reflector glass or plastic material having thecharacteristics of a convex mirror. Spherical segment 31 and base 29have a common upright back wall 36 positioned i a plane normal to flatbottom 30. Wall 36 engages the horizontal edge of cusion rail 12 along alinear line positioning the vertical plane bisecting the segment 31substantially normal to cushion rail 12 so that the light reflectingsurface 32 extends 180 about any given point on the cushion rail.

As shown in FIGURE 2, non-reflective surface 34 and light reflectivesurface 35 supports an indicator 37 located with a longitudinal axis inthe vertical bisecting plane of spherical segment 31. Indicator 37 has adiamond shape and a color, as green, which contrasts with the blackcolor of non-reflective surface 34.

Light reflecting mirror surface 32 is equally divided withcircumferentially spaced radial lines 38 and concentric semicircularlines 39 forming a polar coordinate locating system. Zero radial line 40is located in the vertical plane bisecting spherical segment 31. Eachradial line numbered consecutively on opposite sides of zero radial line40' indicate vertical plane which intersect at the forward point ofindicator 37 which is substantially coincident to impact point 22 oncushion rail 12.

Referring to FIGURES and 6, there is shown a modification of the cueball angle computer of this invention indicated generally at 41positioned on horizontal top surface 42 of a pool table having anupright cushion rail 43. Computer 41 has a flat semicircular shape base44 attached to an upright flat back 46. The bottom surface of base 44 isflat and located normal to a flat outside surface of back 46. Back 46has a horizontal top positioned generally in the horizontal plane of theinwardly directed horizontal edge of cushion rail 43.

Ssecured to the top of base 44 is a member 47 having a light reflectingmirror surface 48- which is semicircular in horizontal outline and has aconvex shape in vertical cross section. Member 47 has a flat top surface49 in alignment with the top of back 46. Surface 49 is coated with alight absorbing material, as black paint. Light reflecting mirrorsurface 48 has circumferentially spaced radial location lines 51dividing the spherical surface into a plurality of radial segments onopposite sides of an upright rib or fin 52 secured to semicircularmember 47 along the vertical plane bisecting light reflecting surface48. The radial location lines 51 intersect with a plurality ofconcentric and semicircular indicator lines 53 forming a polarcoordinate locating system. Lines 51 and 53 may be etched onto the lightreflective surface 48. An indicator 54 in the shape of an arrowheadmounted on the top of the back 46 adjacent opposite sides of the rib 52provides a visual indicator showing impact point 56 on cushion rail 43which must be hit by the cue ball to complete a successful bank shot.

Referring to FIGURES 7, 8 and 9 there is shown a further modification ofthe cue ball angle computer of this invention indicated generally at 57for determining the point of impact that a cue ball must bit in order tocomplete a successful bank shot. Angle computer 57 comprises arectangular flat base 58 secured to a flat upright back 59. Base 58 hasa flat bottom surface located normal to the flat outside face of back59. Base 58 and back 59 form an L-shaped support for a spherical segment61 mounted on base 58 in engagement with back 59. Spherical segment 61is one-quarter of a sphere, as a metal ball, having a one-halfhemispherical convex light reflecting mirror surface 62 located in ahorizontal band above base 58. A non-light reflective surface 63 in theform of a band is located on the sphere below surface 62. In a similarmanner a non-light reflective surface '64 covers the top of sphericalsegments 61.

As shown in FIGURES 8 and 9, back 59 projects upwardly from the top ofspherical segments 61 and carries a horizontally disposed viewing lens66 located above mirror surface 62. Lens 66 is a double convex lenswhich magnifies the images on the light reflective surface or convexmirror 62. Lens 66 may be flat. As shown in FIGURE 7, lens 66 hasparallel grid lines 67 extended longitudinally of the lens in verticalplanes which bisects the vertical plane bisecting spherical segment 61.Lens 66 has a heavy center line 68 indicating the vertical plane whichbisects spherical segment 61. Located on opposite sides of center line68 are a plurality of equally spaced broken lines 69 which intersectlongitudinal lines 67 to provide a rectangular coordinate systemcovering the semicircular light reflecting mirror surface 62.

Longitudinal lines 67 are used in conjunction with the transverse lines69 to accurately align the images of balls 71 and 72 to complementarylocations on opposite sectors of the light reflective mirror surface 62to precisely determine the impact point which the cue ball must strikethe cushion rail in order to complete a bank shot at a selected ball.

In use, the cue ball angle computer is placed on the playing surface 11of the table with the upright back wall 36 in linear engagement with thecushion rail 12. The computer is viewed from above to locate the cueball image as well as the entire playing surface showing the location ofall the balls on the table. In viewing the computer from above when aportion of the viewers image can be seen in light reflective surface 35on opposite sides of indicator 37 the viewer is in correct alignment forsighting the cue ball and the ball selected to be hit with the cue ball.After the cue ball has been located and the ball selected to be hit, forexample, ball 17, the computer is moved along the cushion rail to theright or the left until the images of cue ball 16A and ball 17A arelocated on opposite sides of the bisecting line 40 at the same numericalgrid location shown as number 2 in FIGURE 3. The forward end of diamondindicator 37 points to the location of impact point 22 on cushion rail12 which cue ball 16 must hit for it to rebound into ball 17 as shown inbroken lines in FIGURE 1.

In viewing mirror surface 32 of the computer from above, all other ballsare visible. In the event that a ball is between cue ball 16 andselected ball 17 it is impossible to strike ball 17 and because at leastone nonselected ball is in the rolling path of the cue ball. Under theseplaying conditions it is impossible to make the bank shot from theselected cushion rail. One of the remaining three cushion rails must beused to perfect a bank shot at the selected ball. The angle computer isused with any of the other three cushion rails to determine if there isa bank shot available to strike the selected ball with the cue ball.

In the modified cue ball angle computer 57, shown in FIGURES 7, 8 and 9,spherical light reflecting mirror surface 62 is viewed through the lens66 providing a visual indication of the entire table and of all theballs located on the table. Computer 57 is moved along the cushion railfrom left to right until the cue ball and the selected ball are locatedon opposite sides of the center line 68 as well as along the same gridline 67. The end of the center line will indicate the exact impact pointon the cushion rail that the cue ball must hit so that the cue ball willrebound into the selected ball.

Various omissions, changes in form and details of the cue ball anglecomputer, as illustrated, and described in the preferred embodiments,may be made by those skilled in the art without departing from theinvention as defined in the following claims.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. A computer for indicating an impact point on a cushion rail of a pooltable that a cue ball must hit to complete a bank shot at a selectedball comprising: light reflecting mirror means showing an image of theentire pool table, said mirror means having aligning means engageablewith a cushion rail for aligning the mirror means with said cushion railand a generally convex curved reflector surface symmetrical about thealigning means, said reflector surface being symmetrical about andbisected with a vertical plane, said aligning means when located inengagement with a cushion rail positions the vertical plane normal tothe cushion rail whereby the impact point on the cushion rail isindicated when the images of the cue ball and the selected ball are incorresponding locations on the reflector surface on opposite sides ofthe vertical plane.

2. The computer defined in claim 1 wherein said reflector surface isone-half of a hemisphere.

3. The computer defined in claim 1 including a base having a means tohorizontally position the computer on the playing surface of a pooltable, said light reflect ing mirror means being mounted on said base.

4. The computer of claim 1 including magnification viewing lens meanslocated over said light reflecting mirror means and means supportingsaid lens means over said mirror means.

5. The computer defined in claim 1 including location line meansdividing the reflector surface into substantially equal areas toaccurately determine the corresponding locations of the cue ball imageand selected ball image.

6. The computer defined in claim 5 wherein said location line means areon the reflector surface in a polar coordinate arrangement.

7. The computer defined in claim 1 wherein the refiector surface is ahorizontal curved band extended from a vertical surface engageable witha cushion rail of a pool table and a base supporting the mirror means,said base having a horizontal flat bottom.

References Cited UNITED STATES PATENTS 1,311,253 7/1919 Stern. 1,457,2695/1923 Rexford 350-293 2,904,890 9/1959 Vajda.

JEWELL H. PEDERSEN, Primary Examiner O. B. CHEW II, Assistant ExaminerU.S. Cl. X.R.

